The present application generally relates to information processing apparatuses and methods, content management systems, information recording media, and computer programs. More particularly, the application relates to an information processing apparatus and method, a content management system, an information recording medium, and a computer program in which the use of content is managed on the basis of management units, and the playback operation of content or downloading of data generated or obtained afterwards (subsequently generated/obtained data) is controlled by using playback programs forming content management units.
Various software data (hereinafter referred to as “content”), such as audio data (e.g., music), image data (e.g., movies, game programs, and various application programs), can be stored on recording media, for example, Blu-ray Disc™ using blue laser light, digital versatile discs (DVDs), mini discs (MDs), compact discs (CDs), as digital data. In particular, Blu-ray Discs™ using blue laser light are high-density recording discs and can record a large volume of video content as high-quality image data.
Digital content is stored in various information recording media, such as those described above, and is provided to users. A user uses the digital content by playing it back on the user's personal computer (PC) or a player, such as a disc player.
Generally, the distribution rights of many content data, such as music data and image data, are owned by creators or sellers of such content data. Basically, therefore, certain usage restrictions are imposed when distributing content, that is, the use of content is allowed only for authorized users, thereby preventing unauthorized copying.
According to digital recording apparatuses and recording media, images and sound can be repeatedly recorded and played back without a loss in quality. Thus, the distribution of illegally copied content via the Internet, the circulation of recording media, such as compact disc recordable (CD-R) discs, recording copied content thereon, so-called “pirated discs”, the use of copied content stored in hard disks of, for example, PCs, are widespread.
DVDs or large-capacity recording media, such as those using blue laser light which have recently been developed, can record a large volume of data, for example, up to several movies, on one medium, as digital information. Since video information can be recorded as digital information as described above, it is becoming important to perform copyright protection by preventing unauthorized copying. Nowadays, to prevent unauthorized copying of digital data, various techniques for preventing unauthorized copying are practically applied to digital recording apparatuses or recording media.
For example, in DVD players, a content scrambling system is employed. According to the content scrambling system, data such as video data or sound data is encrypted and recorded on, for example, a digital versatile disc read only memory (DVD-ROM), and a key for decrypting the encrypted data is supplied to licensed DVD players. A license is given to DVD players that are designed in compliance with predetermined operation rules, for example, agreeing not to perform unauthorized copying. Accordingly, licensed DVD players can decrypt data recorded on a DVD-ROM by using the given key to play back images or sound from the DVD-ROM.
On the other hand, unlicensed DVD players are unable to play back data recorded on the DVD-ROM since they do not have the key for decrypting the encrypted data. In this manner, in the content scrambling system, DVD players that do not satisfy conditions demanded for receiving a license are unable to play back digital data from a DVD-ROM, thereby preventing unauthorized copying.
A sufficiently secure management system is constructed for content stored in information recording media, as described above. In current systems, however, the total exclusion of the unauthorized use of content is difficult. For example, configurations in which data is generated afterwards by executing a program recorded on a DVD-ROM or data or content is obtained from external servers are disclosed in Japanese Unexamined Patent Application Publication Nos. 2004-087062 and 2003-308645. It is however difficult to implement the secure data management or usage management by the configurations disclosed in the above publications.